Alkylated polyalkylene polyamines and process for selective alkylation

ABSTRACT

A branched chain polyalkylene polyamine (&#34;PAPA&#34;) having plural amine groups, including a secondary amine group intermediate terminal primary amine groups one of which is hindered, and having at least two carbon atoms between each group, is selectively reductively alkylated with a ketone. The reaction provides a convenient method for selectively reductively alkylating a PAPA having a hindered primary amine group, the method comprising contacting the PAPA with hydrogen and the ketone in the presence of a catalytically effective amount of a Group VIII metal on a catalyst support, at a pressure in the range from about 500-1000 psi and a temperature in the range from about 50° C. to about 200° C. for a period of time sufficient to preferentially alkylate the unhindered amine primary terminal amine group. The alkylation proceeds essentially without alkylating either the sterically hindered terminal primary amine group or the intermediate unhindered secondary amine group.

BACKGROUND OF THE INVENTION

This application is a continuation-in-part of Ser. No. 103,779 filedOct. 2, 1987, now abandoned which is in turn a continuation-in-part ofSer. No. 786,765 filed Oct. 11, 1985, now abandoned, which is in turn acontinuation-in-part of Ser. No. 664,901 filed Oct. 26, 1984, now issuedas U.S. Pat. No. 4,547,538 which is in turn a continuation-in-partapplication of Ser. No. 350,536 filed Feb. 2, 1982 now issued as U.S.Pat. No. 4,480,092.

This invention relates to novel monoprimary-disecondary triamines and amethod for their preparation from polyalkylene polyamines ("PAPA" forbrevity). Such monoprimary-disecondary amines are useful as stabilizersfor organic polymers, for use as curing agents for epoxy resins, and asstarting materials for the preparation of polysubstituted piperazinonesdisclosed in the related prior case U.S. Pat. No. 4,547,538 issued Oct.11, 1985, the disclosure of which is incorporated by reference theretoas if fully set forth herein.

Though it would seem that alkylation of a PAPA should be relativelystraightforward, the reaction between alkyl halides and primary aminesis not usually a feasible method for the preparation of an expectedalkylated product amine, because the reaction does not stop afteralkylation of the primary amine group, even if this is the only aminegroup in the amine reactant. Secondary amines are stronger bases thanthe amine reactant substrate, and therefore the secondary amine grouppreferentially attacks the alkyl halide yielding a tertiary amine.Therefore when both primary and secondary amine groups are present inthe amine to be alkylated, a wide assortment of alkylated products isformed even under the most controlled conditions (see "Advanced OrganicChemistry Reactions, Mechanisms and Structures" by J. March, 3d edition,btm of pg. 365 John Wiley & Sons 1984.) For this reason, generally,alkylation with an alkyl halide is used where a tertiary amine isdesired and one expects to effect complete alkylation of all aminegroups. Even carefully controlled conditions generally give a mixture ofalkylated products and is not favored even on a laboratory scale.

Alkylation of PAPA has been of considerable interest in the past andmethods have been reported by Agnew, N. H. in Journal Chemical Society(London) Sec. C pg 203-208 (1966), and in U.S. Pat. No. 3,051,751. Aprocess for selectively alkylating the secondary amino groups in a PAPAwas disclosed in U.S. Pat. No. 3,565,941 and monotertiary-diprimarytriamines are disclosed in U.S. Pat. No. 3,280,074.

A process is disclosed in U.S. Pat. No. 3,151,160 to Spivack for thepreparation of tertiary-amino-alkylated primary amines in which thebridge nitrogen is tertiary. As Spivack states, even in this alkylationreaction where a very large excess of the reactant amine is used, thismethod is limited to only the simpler diamines because the inherentnon-selective nature of the reaction leads to more or less randomsubstitution of other replaceable hydrogens which results in drasticreduction in yields in the case of somewhat complex reactant amines.Spivack reiterates what has always been the problem with respect to thepreparation of amines represented by structures which, on paper, lookquite obvious. It is not obvious how one can go about obtaining anessentially pure amine by any type of alkylation reaction, evenreductive alkylation.

By "essentially pure" I refer to an amine product of specified structurewhich is at least 90% pure.

The preparation of diprimary triamines having a secondary or tertiary Natom intermediate primary end groups is disclosed in U.S. Pat. No.4,293,682. Because each of the C atoms adjacent the primary amine endgroups (referred to as "N-adjacent C atom") is disubstituted, theprimary amine end groups are hindered and such diprimary PAPA are notsusceptible to the selective alkylation process of this invention inwhich the alkylated product is to have only one primary end groupalkylated. Where a PAPA triamine has only one hindered primary amine endgroup, the other end group being unhindered, one might expect that onlythe unhindered amine group would be alkylated under conventionalalkylation conditions, but both amine end groups are often alkylated,and maybe also the secondary amine.

U.S. Pat. No. 2,393,825 to Senkus teaches that a nitroamine may beprepared by reacting a primary or secondary amine with formaldehyde toform the corresponding N-hydroxymethyl, mono-, or dialkylamine, which isin turn reacted with an equimolar quantity of a secondary nitroparaffinto produce the desired nitroamine. This series of reactions may beillustrated as follows:

    R.sup.1 NH.sub.2 +HCHO→R.sup.1 NHCH.sub.2 OH

the addition occurring at the terminal amine group, whether primary orsecondary. If there were two amine groups, the addition reaction wouldbe expected to occur at each amine group, though not to the same extent,particularly if one amine group was primary and the other was secondary.

Thereafter, the N-hydroxyalkylamine is reacted with a secondarynitroalkane, thus: ##STR1## In an analogous manner, one may start with asecondary amine R¹ -NH-R and HCHO to produce ##STR2## Afterhydrogenation of the nitroamine, the general formula of the polyamineswhich are made by the Senkus procedure is represented as follows:##STR3## wherein R may be H, alkyl, or hydroxyalkyl; R¹ may be alkyl orhydroxyalkyl; and, R² and R³ are alkyl.

In each case, the nitro group may be hydrogenated if the nitro group ison the tertiary C atom of a primary or secondary amine. But in Senkus'reduced compound (with the primary amine group), R¹ and R cannot both beH.

If the starting material is a diamine, rather than a primary or asecondary monoamine, and one tried to form a product with only oneN-hydroxymethylamine group, one might use only a single mole of HCHOwith the expectation that only one of the amine groups in the startingdiamine would be hydroxymethylated. It would then be possible with thismodification of the teaching of Senkus, to produce a compound which issimilar to the precursor of our claimed PAPA.

Pursuing this modification of Senkus one would react nitropropane,formaldehyde and ethylenediamine as follows: ##STR4## This nitroaminewould then be hydrogenated to yield ##STR5## Because it is essentialthat the unhindered primary amine group be substituted, one would expectthat the polyamine could be alkylated as suggested by Kyrides in U.S.Pat. Nos. 2,267,204 and 2,267,205.

The Kyrides polyamine is represented as follows:

    X--NH--R--(NH--R).sub.n --NH--Y

which is formed by an alkylation reaction with a primary alkyl group, tointroduce a long chain alkyl group in the structure. He defines: X is Hor alkyl, R is an alkylene radical, and Y is alkyl. He states that bothX and Y may preferably be the normal (straight chain) alkyl groups;however, forked or branched chain alkyl groups may be employed. (see'204, col 1, lines 43-46).

For our comparison purposes, X must be H. In the '204 and '205 patents,Y is a predominantly straight chain primary alkyl group, though hestates (in '204) it may be branched. By "branched" he refers to aprimary alkyl group derived from a primary alkyl halide, and not to asecondary alkyl group. In his example, 2-ethylhexyl is branched, butnote that it is a primary alkyl group. The reason for his use of primaryalkyl groups is because the secondary alkyl groups will not alkylate theamine in his method. The reaction does not proceed because of the sterichindrance at the halogen-bearing carbon atom.

We attempted to alkylate a large excess of the diamine,N-(2-amino-2-methylpropyl)-1,2-ethanediamine, obtained by hydrogenatingthe compound N-(2-methyl-2-nitropropyl)-1,2-ethanediamine having thestructure: ##STR6## (made as described in our U.S. Pat. No. 4,698,446)with 1-chlorocyclohexane. There was no trace of the alkylated product inthe reaction mass.

The difficulty of alkylating an amine with a secondary alkyl group iswell known. For example, in Great Britain 2,070,011 to Jachimowicz,piperazine is alkylated with cyclohexene in the presence of a rhodiumorganometal catalyst and carbon monoxide, to obtain1,4-dicylcohexylmethyl-piperazine as follows: ##STR7## In the alkylatedproduct, the resulting linkage is through CH₂, which is a primarylinkage derived from the CO. Therefore this alkylation procedure wouldnot result in our claimed compound.

Thus, the difficulty of obtaining anyN-(2-propyl)-N'-(2-amino-2-methylpropyl)-1,2-diaminoethane, let aloneessentially pure product, is evident. It will also be clear to thoseskilled in the art that unless the PAPA is essentially pure, its use forany practical application, is constricted.

The direct alkylation of a primary amine used in Kyrides '204 is theresult of an N-alkylation reaction with a primary alkyl group. Thisreaction does not proceed with a secondary alkyl group as explainedhereinabove. For example, our efforts to alkylate our precursor compoundwith 1-chlorocyclohexane does not result in the N-cyclohexylated productbut with the formation of cyclohexene.

Thus, if one were to make a triamine with a Senkus starting materialmodified to include an alkyleneimine linkage, one would end up with atriamine with terminal primary amine groups one being hindered, and theother unable to be alkylated with a secondary alkyl group.

It appears that the '204 compounds can be readily modified. Theisopropyl linkage between two amine groups in the '204 compound wouldappear to be readily substituted with an isobutyl linkage. However, itis essential that the methine C atom in the isopropyl linkage besubstituted or it would not be the claimed compound, for example:##STR8## while the Kyrides compound would be written ##STR9##Specifically, in the N-2-ethylhexylethylene diamine (pg 2, line 46 in'204) the alkyl group is a primary alkyl group, while N-1-ethylhexyl isa secondary alkyl group.

If one was to alkylate to introduce the secondary alkyl group, with arhodium organometal catalyst and CO, the CO will generate a CH₂ linkinggroup making the alkyl group a primary one. To obtain the claimedcompound, the alkyl group must be secondary.

It is important to note that each of the foregoing Kyrides referenceseschews making any suggestion that an essentially pure PAPA is produced,and of course, for use as insecticides or detergents, they need not be.One would also expect that the known catalytic alkylation with anolefin, such as is disclosed in Jachimowicz would provide a mixture ofPAPA, not an essentially pure one.

Since both the hydrohalo elimination and alkylation reactions proceedconcurrently, it is essential that the latter proceed preferentially ifa reasonably pure, useful amine product is to be synthesized.

An appreciation of the magnitude of the difference between alkylationwith a primary alkyl halide and a secondary alkyl halide may be derivedfrom an examination of the rate constants for the substitution of alkylbromides in 80% ethanol at 55° C. The second-order rate constant(because the reaction is predominantly second order) for isopropylbromide is about 30 times slower than for ethyl bromide (see thetextbook Structure and Mechanism in Organic Chemistry by C. K. Ingold,Table 24-1, pg 318, Cornell University Press).

The elimination reaction (bimolecular olefin formation from alkylbromides) in ethyl alcohol at 25° C. has a rate constant of 11800 forisopropyl bromide, but only 2500 for ethyl bromide; this shows thatelimination with a secondary halide is more than 4.5 times faster (seeIngold, supra, Table 31-7, pg 437).

In particular, we find that if the reaction of1-chloro-2-methyl-2-aminopropane with N-(2-propyl)-1,2-diaminoethaneyields any N-(2-propyl)-N'-(2-amino-2-methylpropyl)-1,2-diaminoethane atall, it is formed in so small an amount that it would not be feasible toseparate it from its isomerN'-(2-amino-2-methylpropyl)-N'-(2-propyl)-1,2-diaminoethane, which isalso formed, not to mention the many other alkylated products which arepredominantly formed.

The reductive alkylation of PAPA is well known and described withnumerous examples in the chapter entitled "Preparation of Amines byReductive Alkylation" by W. S. Emerson in Organic Reactions, Vol 4, JohnWiley & Sons, New York, N.Y. Examples are given for preparation (A) oftertiary amines from (i) secondary aliphatic amines and ketones, (ii)aryl alkyl amines and aliphatic aldehydes, (iii) aryl alkyl amines andketones; etc., and, (B) of secondary amines by (i) reduction of Schiff'sbases derived from aliphatic amines, and from aromatic amines, and (ii)reduction of primary aromatic amines, nitro or nitroso compounds andketones, etc. In reductive alkylations with an aldehyde there is a widescatter of side reaction because of the higher reactivity of an aldehydethan a ketone. There is no teaching that reductive alkylation with aketone may result in alkylation only at a particular amino groupsubstantially to the exclusion of all other amino groups, such resultbeing obtained with a PAPA only by hindering one of the two primaryamine groups and reacting with a ketone.

SUMMARY OF THE INVENTION

It has been discovered that an essentially pure alkylatedpolyalkylenepolyamine ("PAPA") can be obtained by a novel selectivereductive alkylation reaction.

It has also been discovered that the reaction of a branched chain PAPAhaving plural amine groups including a secondary amine groupintermediate terminal primary amine groups one of which is hindered, andhaving at least two carbon atoms between each group, may be selectivelyreductively alkylated with a ketone in an unexpectedly different mannerfrom the known reaction of a PAPA with an aldehyde, wherein the PAPA hasno hindered amine group.

It is therefore a general object of this invention to provide a processfor selectively reductively alkylating a PAPA having a hindered primaryamine group, comprising contacting said PAPA with hydrogen and a ketonein the presence of a catalytically effective amount of a Group VIIImetal on a catalyst support, at a pressure in the range from about500-1000 psi and a temperature in the range from about 50° C. to about200° C., preferably using an inert solvent for the reactants, for aperiod of time sufficient to preferentially alkylate the unhinderedamine primary terminal amine group, essentially without alkylatingeither the sterically hindered terminal primary amine group or theintermediate secondary amine group.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Epoxy resins containing plural oxirane moieties in each chain arecurable with polyamines among which the PAPA such as ethylene diamine,diethylene triamine, triethylene tetramine, and the like are effectiveat room temperature. However, such PAPA have short pot life, aredifficult to use for one reason or the other including being toovolatile, having unacceptably high toxicity, etc., and, the cured epoxyresins are often highly brittle and lack impact resistance.

To combat the foregoing drawbacks PAPA have been modified, for example,the short chain alkyl derivatives, or by reaction with fatty acids toform amino amides and amino polyamides. But such compounds are generallytoo viscous for easy use and do not offer the option of tailoring themeasily. The process of this invention enlarges the scope of the types ofalkylated PAPA which may be prepared and allows those which arespecifically desired to be tailored substantially to the exclusion offorming unwanted compounds.

The process comprises reductively alkylating a particular class of PAPA,such as a N'-(aminoalkyl)-1,p-alkanediamine,N'-(aminoaryl)-1,p-alkanediamine, N'-(aminoaralkyl)-1,p-alkanediamine,and, N'-(aminocycloalky)-1,p-alkanediamine (hereafter collectivelyreferred to as N'-(aminoalkyl/aryl/aralkyl/cycloalky)-1,p-alkanediamine,wherein `p` corresponds to the number of C atoms in the diaminoalkane,and "2AD" for brevity) with an aliphatic, alicyclic or heterocyclicketone in the presence of a Group VIII metal hydrogenation catalyst andan inert solvent for the reactants under hydrogenation conditions, bycarrying out the reaction under elevated pressure and temperature toproduce a N-(alkyl/piperidyl)-N'-(aminoalkyl/aryl/aralkyl/cycloalky)-1,p-alkanediamine which is thereductively alkylated ("2AAD" for brevity) product.

Preferred metals are Raney nickel, finely divided iron, cobalt,platinum, palladium, ruthenium, osmium, rhenium and rhodium, any one ofwhich is to be supported on pumice, asbestos, kieselguhr, alumina,silica gel or charcoal. The amount of catalyst used depends upon theprocess conditions and also upon the reactants, from about 0.01% toabout 10% by wt of the 2AD giving satisfactory results.

The ketone used may be any branched or unbranched aliphatic ketones,preferably having from 3 to about 20 carbon atoms, for example acetone,butanones, pentanones; alicyclic ketones, preferably having from 5 toabout 8 carbon atoms, for example cyclopentanone, cyclohexanone,cyclooctanone; and, piperidinone which may be ring-substituted,preferably with C₁ -C₂₀ alkyl and/or C₅ -C₈ cycloalkyl spirosubstituents, most preferably at the N-adjacent (2,6 positions) C atoms.

The most readily available preferred inert solvents are aliphatic andalicyclic hydrocarbons which are solvents for the reactants, but whichresist reduction under the conditions of reaction. Particularly usefulare the C₁ -C₁₀ alkanes, such as hexane, and the alcohols such as theprimary lower C₁ -C₆ alcohols, though secondary alcohols such asisopropyl alcohol, or tertiary alcohols such as t-butyl alcohol may alsobe used.

The epoxy resins which can be cured at elevated temperatures using the2AAD compounds of this invention are those polyepoxides possessing atleast two oxirane groups which may be internal or terminal. Thepolyepoxides may be saturated or unsaturated, aliphatic, cycloaliphatic,aromatic or heterocyclic, and may be substituted such as with hydroxylgroups, ether radicals and the like. Further, the polyepoxides may bemonomeric or polymeric. Such polyepoxides, and their preparation, arewell known in the art.

The curing of the polyepoxides with the 2AAD curing agents may beaccomplished by simply mixing the two components together, the 2AADbeing present in an amount in the range from about 5 to about 35 partsper 100 parts by wt of epoxy resin. While the reaction between the twocomponents occurs slowly at room temperature, acceleration of the cureis obtained if the mixture is heated to a temperature in the range fromabout 50°-100° C. for a period of time from about 0.5 to about 2 hr, andthereafter post-curing the reaction product for an additional period oftime from about 2 to about 5 hr at elevated temperature above 100° C.

To cure a polyepoxide it is generally desirable that it be in a fluidcondition when the 2AAD is added to facilitate obtaining a homogeneousmixture. If the polyepoxide is too viscous at room or castingtemperature, it may be heated to reduce the viscosity, or a fugitivevolatile liquid solvent may be added. During curing and post-curing thesolvent escapes by evaporation. Typical of such volatile liquid solventsare ketones, such as acetone, methyl ethyl ketone, and the like; esters,such as ethyl acetate, butyl acetate and the like; ether alcohols suchas methyl, ethyl or butyl ethers of ethylene glycol, and chlorinatedhydrocarbons such as chloroform.

In addition to their use as curing agents for epoxy resins the 2AADcompounds may be cyclized to yield polysubstituted piperazinones whichare UV stabilizers, and substituted oxo-piperazinyl-triazines asdisclosed in our U.S. Pat. Nos. 4,480,092 and 4,639,479.

The foregoing reductive alkylation process may be effectively practicedwith any PAPA having the general structure ##STR10## wherein, R_(a) andR_(b) independently represent alkyl having from 1 to 24 carbon atoms,aryl having from 6 to 10 carbon atoms, particularly phenyl, and aralkylhaving from 7 to about 24 carbon atoms;

R_(a) or R_(b) may be cycloalkyl; or,

R_(a) and R_(b) together when cyclized may be cycloalkyl having from 5to about 7 carbon atoms; and,

p represents an integer in the range from 2 to 10.

When the process is practiced with an aliphatic ketone having from 3 toabout 20 carbon atoms, preferably a lower C₃ -C₉ ketone, or acycloaliphatic ketone having from 5 to about 20 carbon atoms andhydrogenation is effected over a Group VIII metal on a suitable catalystsupport at a pressure in the range from about 500 psi to about 1000 psiand a temperature in the range from about 50° C. to about 200° C., noreaction product is isolated which is alkylated at either theintermediate amine group or the hindered terminal amine group.

The alkylated PAPA formed, referred to as the 2AAD compound, may berepresented by the following general structure: ##STR11## wherein, R_(c)and R_(d) independently represent branched or unbranched alkyl havingfrom 1 to 24 carbon atoms, aralkyl having from 7 to about 24 carbonatoms;

R_(c) or R_(d), one or both may be cycloalkyl; or,

R_(c) and R_(d) together when cyclized may be cycloalkyl having from 5to about 7 carbon atoms, or, piperidyl which may be substituted at oneor both of the N-adjacent carbon atoms in the piperidyl ring, each Catom with one, preferably two lower C₁ -C₆ alkyl substituents, or,substituted at one C atom, preferably both N-adjacent C atoms with acycloalkyl spiro substituent; and,

R_(a), R_(b), and p have the same connotation as that given hereinabove.

Preparation of 2AAD Compound

In a typical reaction, the 2AAD compound is prepared fromN-(2-amino-2-methylpropyl)-1,2-ethanediamine and a ketone selected toprovide particularly desirable physical properties in the 2AAD, forexample an agreeable odor, and minimal toxicity, or to provide thedesired steric hindrance in the 2AAD compound if it is to be used forthe preparation of polysubstituted piperazinones. The preparation ofparticular 2AAD compounds is illustrated in the following examples.

EXAMPLE 1 Preparation ofN-(2-butyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine having thefollowing structure ##STR12## A mixture of 146 g (1.1 moles) ofN-(2-amino-2-methylpropyl)-1,2-ethanediamine, 84.4 g (1.17 moles) of2-butanone, 300 ml methanol, and 3.0 g of 10% platinum on carbon werereacted in a 1 liter autoclave at 80° C. under 800 psi hydrogenpressure. After two hours the reaction mixture was cooled, then filteredto remove the catalyst. The filtrate was stripped to give 205.3 g ofwater-white clear liquid which was fractionally distilled under reducedpressure. The desired product recovered was found to weigh 144.5 g(69.5% yield), was about 95% pure, and has a boiling point (b p) of62°-64° C./0.15 mm Hg.

The structure written hereinabove is supported by both proton nuclearmagnetic resonance (NMR), and field desorption (FD) mass spectroscopicdata.

EXAMPLE 2 Preparation ofN-(4-methyl-2-pentyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine

In an analogous manner, other dialkyl substituents may be substituted atthe N position. For example,N-(4-methyl-2-pentyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine maybe prepared from N-(2-amino-2-methylpropyl)-1,2-ethanediamine and4-methyl-2-pentanone by reductive alkylation in propanol. The compoundobtained in excellent yield is found to be more than 90% pure, and havea b p of 100°-109° C./0.3 mm Hg.

EXAMPLE 3 Preparation ofN-(2-propyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine having thefollowing structure ##STR13## In a stirred autoclave place a mixture of146 g of N-(2-amino-2-methylpropyl)-1,2-ethanediamine, 64 g acetone, 250ml of methanol, and 7 g of 3% platinum on charcoal, and hydrogenate themixture under 1500 psi H₂ pressure in a heated autoclave maintained at150° C. After about 5 hr the reaction mixture is cooled, filtered toremove the catalyst, and concentrated. The desired product is obtainedin 92% pure form which may be further purified by distilling at 90°-95°C./8 mm Hg to yield a colorless oil. The pure product boils at 96°-98°C./8 mm Hg.

The structure written above is supported by both proton NMR and FD massspectroscopic data.

EXAMPLE 4

In an analogous manner, a cycloalkyl, a piperidyl (optionallysubstituted at the N-adjacent C atoms), an aryl or aralkyl substituentmay be substituted at the N position as for example, by preparingN-cyclohexyl-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine having thefollowing structure: ##STR14## The desired compound is obtained byreacting N-(2-amino-2-methylpropyl)-1,2-ethanediamine with cyclohexanonein methanol in the presence of 10% Pt on carbon by hydrogenation at 80°C. under 800 psi. The desired compound is obtained in 98% pure form byfractionation at reduced pressure and has a b p of 96°-104° C. at 0.7 mmHg.

In a manner analogous to that described immediately hereinabove, byreacting N-(2-amino-2-methylpropyl)-1,2-ethanediamine withpiperidin-4-one, it is reductively alkylated to yieldN-(4-piperidyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine; and,2,2,6,6-piperidin-4-one is reductively alkylated to yieldN-(2,2,6,6-tetramethyl-4-piperidyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediaminehaving the structure: ##STR15##

In a manner analogous to that described herein above, the following 2AADcompounds are prepared:

N-(2-propyl)-N'-(2-amino-2-ethylbutyl)-1,2-ethanediamine;

N-cyclohexyl-N'-(2-amino-2-ethylbutyl)-1,3-propanediamine;

N-(4-piperidyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine;

N-(2,2,6,6-tetramethyl-4-piperidyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine;

N-(2-octyl)-N'-(2-amino-2-ethylbutyl)-6-hexanediamine;

N-(2-propyl)-N'-(2-amino-2-2-diphenylethyl)-1,2-ethanediamine;

N-cyclohexyl-N'-(2-amino-2-2-diphenylethyl)-1,6-hexanediamine;

N-(2-propyl)-N'-(1-aminocyclohexylmethyl)-1,2-ethanediamine; and,

N-cyclohexyl-N'-(1-aminocyclohexylmethyl)-1,6-hexanediamine.

It will now be evident that a wide variety of substituents may be madein the 2AAD compounds formed, and the effect of each can be judged bysimple trial and error until the optimum properties are obtained for thepurpose at hand.

Of course, such optimum properties of a PAPA can best be judged onlywith an essentially pure mass of the desired PAPA which is free from anycyclic PAPA, and free from those acyclic PAPA alkylated at secondaryamino groups which result in unwanted PAPA. We know of no process, otherthan the one we have disclosed hereinabove, which will provide theessentially pure mass of PAPA.

Note, that in the foregoing specification, the term N-(alkyl/piperidyl)is used to identify the PAPA which has been alkylated at the unhinderedprimary amine group with either an alkyl group or a piperidyl group asillustrated in the examples provided.

We claim:
 1. An essentially pure alkylated polyalkylenepolyamine havingthe structure ##STR16## wherein, R_(a) and R_(b) independently representalkyl having from 1 to 24 carbon atoms, and aralkyl having from 7 toabout 20 carbon atoms or cycloalkyl; or,R_(a) and R_(b) together whencyclized form a cycloalkyl having from 5 to about 7 carbon atom; R_(c)and R_(d) independently represent branched or unbranched alkyl havingfrom 1 to 24 carbon atoms, aralkyl having from 7 to about 20 carbonatoms or cycloalkyl; R_(c) and R_(d) together when cyclized form acycloalkyl having from 5 to about 7 carbon atoms, unsubstitutedpiperidyl or substituted piperidyl wherein said substituents are one ormore alkyl or spiro cycloalkyl at one or both of the N-adjacent carbonatoms; and, p represents an integer in the range from 2 to
 10. 2. Theessentially pure composition of claim 1,including:N-(2-propyl)-N'-(2-amino-2-ethylbutyl)-1,2-ethanediamine;N-cyclohexyl-N'-(2-amino-2-ethylbutyl)-1,3-propanediamine;N-(2-octyl)-N'-(2-amino-2-ethylbutyl)-1,6-hexanediamine;N-(2-butyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine;N-(4-methyl-2-pentyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine;N-(2-propyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine;N-cyclohexyl-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine;N-(4-piperidyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine;N-(2,2,6,6-tetramethyl-4-piperidyl)-N'-(2-amino-2-methylpropyl)-1,2-ethanediamine;N-(2-propyl)-N'-((1-aminocyclohexyl)methyl)-1,2-ethanediamine; or,N-cyclohexyl-N'-((1-aminocyclohexyl)methyl)-1,6-hexanediamine.